A while ago I bought a Trek 7.2 FX (steel fork, aluminum frame, and yes the fork passes the magnet test) and slowly converted it with the "Phoenix Racer" (Crystalyte X-5) kit from electricrider.com. I finally got it working and functional late last night and took it for a very brief nighttime ride, though I barely used the motor and mostly pedalled since it was dark and I had no reflectors, let alone lights! Also I wanted to see how easy it was going manual, and it turned out to be effortless.
Today was a beautiful day so I got ready to take it out again, though I noticed the front bolts were somehow loose even though I'd tightened them tightly before. Oh, by the way, I was not using the hook thing for the fork because it did not fit. The dropouts for my fork are not vertical like the kit assumes; they're diagonal, and the only way to fit the wheel was to remove that thing and even the guards around the wires.
Anyway I retightened the bolts with a pair of pliers and tried to take it out, but the motor wouldn't work! Then I noticed the wires had been twisted around the axle 270 degrees, so I removed the bolts and discovered the axle had rotated 90 degrees within the fork, stretching it out so the dropout is almost square. D'oh!
So now I have a dead motor and a dangerous fork that I need to replace. The axle (I don't know the correct terminology) is evidently alot tougher than the steel fork. And I never even got to take it for a real drive yet.